From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/rtc/rtc-imx-sc.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 drivers/rtc/rtc-imx-sc.c (limited to 'drivers/rtc/rtc-imx-sc.c') diff --git a/drivers/rtc/rtc-imx-sc.c b/drivers/rtc/rtc-imx-sc.c new file mode 100644 index 000000000..814d51664 --- /dev/null +++ b/drivers/rtc/rtc-imx-sc.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2018 NXP. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define IMX_SC_TIMER_FUNC_GET_RTC_SEC1970 9 +#define IMX_SC_TIMER_FUNC_SET_RTC_ALARM 8 +#define IMX_SC_TIMER_FUNC_SET_RTC_TIME 6 + +#define IMX_SIP_SRTC 0xC2000002 +#define IMX_SIP_SRTC_SET_TIME 0x0 + +#define SC_IRQ_GROUP_RTC 2 +#define SC_IRQ_RTC 1 + +static struct imx_sc_ipc *rtc_ipc_handle; +static struct rtc_device *imx_sc_rtc; + +struct imx_sc_msg_timer_get_rtc_time { + struct imx_sc_rpc_msg hdr; + u32 time; +} __packed; + +struct imx_sc_msg_timer_rtc_set_alarm { + struct imx_sc_rpc_msg hdr; + u16 year; + u8 mon; + u8 day; + u8 hour; + u8 min; + u8 sec; +} __packed __aligned(4); + +static int imx_sc_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct imx_sc_msg_timer_get_rtc_time msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + int ret; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_TIMER; + hdr->func = IMX_SC_TIMER_FUNC_GET_RTC_SEC1970; + hdr->size = 1; + + ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true); + if (ret) { + dev_err(dev, "read rtc time failed, ret %d\n", ret); + return ret; + } + + rtc_time64_to_tm(msg.time, tm); + + return 0; +} + +static int imx_sc_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct arm_smccc_res res; + + /* pack 2 time parameters into 1 register, 16 bits for each */ + arm_smccc_smc(IMX_SIP_SRTC, IMX_SIP_SRTC_SET_TIME, + ((tm->tm_year + 1900) << 16) | (tm->tm_mon + 1), + (tm->tm_mday << 16) | tm->tm_hour, + (tm->tm_min << 16) | tm->tm_sec, + 0, 0, 0, &res); + + return res.a0; +} + +static int imx_sc_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) +{ + return imx_scu_irq_group_enable(SC_IRQ_GROUP_RTC, SC_IRQ_RTC, enable); +} + +static int imx_sc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct imx_sc_msg_timer_rtc_set_alarm msg; + struct imx_sc_rpc_msg *hdr = &msg.hdr; + int ret; + struct rtc_time *alrm_tm = &alrm->time; + + hdr->ver = IMX_SC_RPC_VERSION; + hdr->svc = IMX_SC_RPC_SVC_TIMER; + hdr->func = IMX_SC_TIMER_FUNC_SET_RTC_ALARM; + hdr->size = 3; + + msg.year = alrm_tm->tm_year + 1900; + msg.mon = alrm_tm->tm_mon + 1; + msg.day = alrm_tm->tm_mday; + msg.hour = alrm_tm->tm_hour; + msg.min = alrm_tm->tm_min; + msg.sec = alrm_tm->tm_sec; + + ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true); + if (ret) { + dev_err(dev, "set rtc alarm failed, ret %d\n", ret); + return ret; + } + + ret = imx_sc_rtc_alarm_irq_enable(dev, alrm->enabled); + if (ret) { + dev_err(dev, "enable rtc alarm failed, ret %d\n", ret); + return ret; + } + + return 0; +} + +static const struct rtc_class_ops imx_sc_rtc_ops = { + .read_time = imx_sc_rtc_read_time, + .set_time = imx_sc_rtc_set_time, + .set_alarm = imx_sc_rtc_set_alarm, + .alarm_irq_enable = imx_sc_rtc_alarm_irq_enable, +}; + +static int imx_sc_rtc_alarm_notify(struct notifier_block *nb, + unsigned long event, void *group) +{ + /* ignore non-rtc irq */ + if (!((event & SC_IRQ_RTC) && (*(u8 *)group == SC_IRQ_GROUP_RTC))) + return 0; + + rtc_update_irq(imx_sc_rtc, 1, RTC_IRQF | RTC_AF); + + return 0; +} + +static struct notifier_block imx_sc_rtc_alarm_sc_notifier = { + .notifier_call = imx_sc_rtc_alarm_notify, +}; + +static int imx_sc_rtc_probe(struct platform_device *pdev) +{ + int ret; + + ret = imx_scu_get_handle(&rtc_ipc_handle); + if (ret) + return ret; + + device_init_wakeup(&pdev->dev, true); + + imx_sc_rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(imx_sc_rtc)) + return PTR_ERR(imx_sc_rtc); + + imx_sc_rtc->ops = &imx_sc_rtc_ops; + imx_sc_rtc->range_min = 0; + imx_sc_rtc->range_max = U32_MAX; + + ret = devm_rtc_register_device(imx_sc_rtc); + if (ret) + return ret; + + imx_scu_irq_register_notifier(&imx_sc_rtc_alarm_sc_notifier); + + return 0; +} + +static const struct of_device_id imx_sc_dt_ids[] = { + { .compatible = "fsl,imx8qxp-sc-rtc", }, + {} +}; +MODULE_DEVICE_TABLE(of, imx_sc_dt_ids); + +static struct platform_driver imx_sc_rtc_driver = { + .driver = { + .name = "imx-sc-rtc", + .of_match_table = imx_sc_dt_ids, + }, + .probe = imx_sc_rtc_probe, +}; +module_platform_driver(imx_sc_rtc_driver); + +MODULE_AUTHOR("Anson Huang "); +MODULE_DESCRIPTION("NXP i.MX System Controller RTC Driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1